pyridinium chlorochromate in dichloromethane 1) 0 deg C, 2) 3 h, r.t.;

1: 60 percent / 25percent DIBAH / tetrahydrofuran; toluene / 1 h / -30 - -25 °C 2: 43 percent / pyridinium chlorochromate / CH2Cl2 / 1) 0 deg C, 2) 3 h, r.t. View Scheme